Hi Anuchida,
If both child records doesn't appear in SO system, we advise you to do the following procedure:
1. Request for a new CH/photo/CGV (if participating in CGV this FY15) of these 2 children from community.
2. Add both records as New child in SingleSTEP.
3. Kindly notify Jen/SSS once #2 is done so that they can validate in the server side.
Let us know if you have any questions.
Thank you.